1,2

Remi Eismann, Table of n, a(n) for n = 1..10000

Join[{1}, Divisors[#][[2]]&/@Range[3, 161, 2]] (* Harvey P. Dale, Oct 09 2011 *)

(PARI) a(n)=if(n>1, factor(2*n-1)[1, 1], 1) \\ Charles R Greathouse IV, Nov 09 2016

Bisection of A020639.

Cf. A100773.

Sequence in context: A255562 A130140 A051417 * A120374 A088836 A076565

Adjacent sequences: A090365 A090366 A090367 * A090369 A090370 A090371

nonn

Lekraj Beedassy, Nov 27 2003

More terms from Ray Chandler, Dec 02 2003

Definition corrected by Rémi Eismann, May 08 2007

approved